Click beetle

Key information

Athous haemorrhoidalis: This elongated beetle has a dark brown thorax and a brown, ridged back. On close inspection its antennae appear toothed.

Agriotes lineatus: Adults are bullet-shaped and their wing cases (elytra) appear lined. They are black or brown all over.

When threatened, attacked or overturned, these beetles can flick themselves into the air emitting an audible click – hence their name. A click beetle does this by flexing the joint between its thorax and abdomen; the tension increases until the peg slips, catapulting the insect into the air. The beetle may not always land on its feet, so will perform this feat several times until it does. Occasionally click beetles jump as high as 30cm.

Click beetle larvae are the notorious wireworms despised by gardeners. They are about 25mm long with shiny, yellow-orange bodies. They spend up to four years underground munching through plant roots and stem bases until pupating and emerging as adult click beetles. They can ruin potato and root crops.